a child could use my 9year old would like to learn the language
you can use some of Brzechwa's short poems (I still have the edition of his "100 bajek")
Dzik jest dziki, dzik jest zły.
Dzik ma bardzo ostre kły.
Kto spotyka w lesie dzika,
Ten na drzewo szybko zmyka.
or something else:
(from anikino.pl/dzieci.php - there are several texts and a few audio files)